C1.5 and C2.2 Industrial Engines Caterpillar

Note: If this fault occurs only under load, refer to Troubleshooting, "Acceleration Is Poor or Throttle Response Is Poor".

Probable Causes

• Diagnostic codes

• ECM parameters

• Throttle signal from the throttle position sensor

• Air intake and exhaust system

• Fuel supply

• Low compression (cylinder pressure)

Recommended Actions

Diagnostic Codes

Use one of the following methods to check for active diagnostic codes:

• The electronic service tool

• The display on the control panel

Electronic Service Tool

1. Connect the electronic service tool to the diagnostic connector.

2. Check for active diagnostic codes on the electronic service tool.

3. Investigate any active codes before continuing with this procedure. Refer to Troubleshooting, "Troubleshooting with a Diagnostic Code".

Display on the Control Panel

Note: The following procedure is only applicable if the application is equipped with a display on the control panel.

1. Check the display on the control panel for active diagnostic codes.

2. Troubleshoot any active codes before continuing with this procedure. Refer to Troubleshooting, "Troubleshooting with a Diagnostic Code".

ECM Parameters

1. Ensure that the fault is not an incorrect or missing programmed parameter.

2. Ensure that the correct mode was selected by using the electronic service tool.

3. Use the electronic service tool to verify the correct engine rating for the engine.

4. Use the electronic service tool to verify the maximum engine speed limit.

5. Use the electronic service tool to verify the following parameters at maximum speed: the boost pressure, the smoke limit, the torque limit and the amount of fuel that is delivered.

6. Use the electronic service tool to reset the parameters to the OEM specifications.

7. Ensure that the repairs have eliminated the fault.

8. If the repairs have not eliminated the fault, proceed to "Throttle Signal for the Throttle Position Sensor".

Throttle Signal for the Throttle Position Sensor

1. Use the electronic service tool and observe the signal for the throttle position sensor. Make sure that the throttle reaches the 100% raw position and the calibrated position.

2. If the signal is erratic, refer to Troubleshooting, "Analog Throttle Position Sensor Circuit - Test".

3. If the fault has not been eliminated, proceed to "Air Intake and Exhaust System".

Air Intake and Exhaust System

1. Check the air filter restriction indicator, if equipped.

2. Ensure that the air filter is clean and serviceable.

3. Check the air intake and the exhaust system for the following defects:

   • Blockages

   • Restrictions

   • Damage to the air intake and exhaust lines and hoses

4. Make all necessary repairs to the engine.

5. Ensure that the repairs have eliminated the fault.

6. If the fault has not been eliminated, proceed to "Fuel Supply".

Fuel Supply

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Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

1. Check for leaks from the high-pressure fuel lines. If the high-pressure fuel lines have a leak, the high-pressure fuel lines must be replaced. Refer to Disassembly and Assembly, "Fuel Injection Lines - Remove" and Disassembly and Assembly, "Fuel Injection Lines - Install".

2. Visually check the fuel tank for fuel. The fuel gauge may be faulty.

3. If equipped, ensure that the fuel supply valve is in the full OPEN position.

4. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).

5. Visually inspect the fuel supply lines for restrictions.

6. Check that the low-pressure fuel lines are tight and secured properly.

7. If equipped, replace the in-line fuel strainer and the fuel pre-filter.

8. Remove the main fuel filter. Inspect the fuel filter for contamination. Install a new fuel filter. Refer to the Operation and Maintenance Manual. Determine the cause of the contamination.

9. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test".

10. Check for air in the low-pressure fuel system and check the pressure in the low-pressure fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".

11. If the fault is still present, proceed to "Low Compression (Cylinder Pressure)".

Low Compression (Cylinder Pressure)

1. Perform a compression test. Refer to Systems Operation, Testing, and Adjusting, "Compression - Test ".

2. If low compression is noted on any cylinders, investigate the cause and rectify the cause.

   Possible causes of low compression are shown in the following list:

   • Loose glow plugs

   • Faulty piston

   • Faulty piston rings

   • Worn cylinder bores

   • Worn valves

   • Faulty cylinder head gasket

   • Damaged cylinder head

3. Perform all necessary repairs.

4. Ensure that the repairs have eliminated the faults.

5. If the repair does not eliminate the fault, contact the Technical Communicator at a Cat® dealer.